"The North launched an unidentified ballistic missile towards [the Sea of Japan]," the South Korean military said in a statement, without providing other details.
A ballistic missile presumably launched by North Korea has already fallen, the Japan Coast Guard said.
"An object believed to be a ballistic missile fired from North Korea has already fallen, according to the Defense Ministry. Vessels should monitor subsequent information and, if wreckage is detected, not approach it, but report the relevant information to the coast guard," the coast guard said in a statement.
The ballistic missile, presumably fired by North Korea toward Japan, has fallen out of Japan's exclusive economic zone, the NHK broadcaster reported, citing Japanese government sources.